code: def test_serialize_union():
      D1 = muda.deformers.LogspaceTimeStretch()
      D2 = muda.deformers.LogspaceTimeStretch()
      U_orig = muda.Union([("stretch_1", D1), ("stretch_2", D2)])
      U_ser = muda.serialize(U_orig)
  
      U_new = muda.deserialize(U_ser)
  
      assert U_orig is not U_new
      assert U_orig.get_params() == U_new.get_params()
  
file_path: muda/tests/test_core.py
imports: import tempfile
  import os
  import six
  import numpy
  import jams
  import librosa
  import muda
  import pytest
label_desc: Use image node_id 8 for calling a global function with example usage: test_serialize_union() without return types